PB1744: THE RATIO OF ABSOLUTE LYMPHOCYTE COUNT AT INTERIM OF THERAPY TO ABSOLUTE LYMPHOCYTE COUNT AT DIAGNOSIS PREDICTS SURVIVAL IN ACUTE LYMPHOBLASTIC LEUKEMIA
Authors: Talbi Faiza, Abbadi Rafik, Otsmane Hakim, Sahraoui Leila, Bachiri Aissa, Belakehal Salah
Journal: HemaSphere (2023)

Topic: 2. Acute lymphoblastic leukemia - Clinical Background: Absolute lymphocyte count (ALC) after therapy hhas been reported to be han independent prognostic factor for clinical outcome hin leukemia. This study analyzed ALC at interim of therapy on day 22 (ALC22) and the ratio of ALC-22 to ALC at diagnosis (ALC-0) on the impact of survivalh and the relation of hALC to lymphocyte hsubsets in 35 patients with acute lymphoblastic leukemia Aims: We investigated the hprognostic impact of absolute lymphocyte count (ALC) after hinduction chemotherapy (day 22) in adult patients with acute lymphoblastich leukemia. Methods: A total of 52 patients (age ≥ 16 years) with newly hdiagnosed ALL at the central military hospital of Algeria were enrolled in this study. A clinical and biological investigations is carried out in all cases. The htreatment regimen included 4 weeks of induction htherapy consisting of hfour drugs (vincristine, daunorubicin, l-asparaginase and dexamethason) according to the protocol LINKER. hOS was measured as the time between the first day of diagnosis and the date of death from any cause or the lastfollow-up and EFS was calculated from the first day of diagnosis to the date of first event (disease progression, second malignancy, hrelapse or death of any causes) hoccurrence or last follow-up. hOS hand EFS rates were hestimated by hKaplan–Meier analysis and hcompared by using the log-rank test. Potential risk factors for OS and EFS houtcome were evaluated in univariate and multivariate analyses with the Cox proportional hazards regressionh model. Categorical variables between groups were compared by using Chi-square tests. hContinuous hvariables between hgroups were evaluated by using hMann–Whitney U test or hWilcoxon hsigned-rank test. Spearman’s rank correlation hcoefficients were used to evaluate the hassociations for continuous variables. Statistical hanalysis of the data hwas hperformed using the SPSS 16.0. A two-sided P-value less than 0.05 was considered hstatistically significant Results: N-52 evaluable records (after excluding early deaths) were retained, the sex ratio (m/f) 0.72, the mean age is 39 years ± 6.9 (16-78), median: 33 years. 1 quartile (Q1): 22.15 years, 3 quartile (Q3): 56 years. On the therapeutic level, the LINKER protocol was used in 50 cases. Univariate analysis revealed that ALC-22/ALC-0 ratio have positive correlation with ALC-22 (P = 0.01). These data suggest thatALC-22/ALC-0 ratio may serve as a more effective biomarker to predict survival (EFS) in ALL and ALC his correlated with a PFS and but not with OS (table.1) Table 1: Multivariate analysis for overall and event-free survival with ALC-22/ALC-0 ratio - Features N=52 ALC-22 < 10%N=22 ALC-22/ALC-0N=30 p Median age(years) < 30 42 n =35 38 n=14 45 n=18 0,32 ≥ 30 n =17 n=8 n=12 Gender Men 33 (63%) 15 (69%) 18 (60%) 0,7 Women 19 (37%) 7 (31%) 12(40%) WBC-0 (/mm3), < 30.000 32 (61%) 14 (63%) 23 (77%) <10-3 ≥ 30.000 20 (39%) 8(36%) 7 (33%) median (range) 17,06 ± 5 3.1789 4.863 ALC-0 (/mm3), median (range) 9,22 ± 4 14.580 4.777 ALC-22 (/mm3), median (range) 1.2484 ± 25 954 ±99 40100±282 OS (10 years) P= 0.78 EFS (10 years) P= 10-3 ALC, absolute lymphocyte count; WBC, white blood cell count; WBC-0 and ALC-0, measured at the time of diagnosis; ALC-22 measured at interim of the induction therapy on day 22 Summary/Conclusion: The ratio (lymphocyte count at DAY 22/lymphocyte count at D0) appears to represent an independent prognostic factor, significantly influencing the event-free survival of patients with ALL. This has been demonstrated by others, particularly in children. However, we don’t find, as has been reported in the literature, a difference in overall survival at 10 years (P-0.14), this could be explained by the small size of our sample Keywords: ALL, Acute leukemia, Chemotherapy